“My guess is this agreement is going to happen,” said Corker at Belmont University. “At the end of the day, I don’t think there’s likely going to be a veto-proof number of people to keep it from occurring.”

Congressional Republicans have been organizing to pass a resolution designed to block the Iran nuclear deal. However, President Barack Obama would surely veto such a resolution. Republicans in both chambers would have a difficult time gathering the two-thirds majority needed to override a presidential veto.

Senate Majority Leader Mitch McConnell (R-KY) noted that Obama could win the battle by winning one-third plus one in each chamber. Congressional Democrats may be the minority in each chamber, but there are enough to protect the Iran nuclear deal from Republican obstruction. Republicans would need to persuade at least 13 of the 46 Senate seats held by Democrats to override the deal.

Only two Senate Democrats have announced their opposition: Sens. Chuck Schumer (D-NY) and Bob Menendez (D-NJ).

Republicans are finally starting to realize that they can’t obstruct the Iran nuclear deal. Provided the party doesn’t win the White House next year, which seems unlikely at this point, the deal is rock solid.